Sign & Verify Files
Embed an invisible authenticity signal into images and PDFs, then verify whether a signed file still matches its authenticated state.
Sign a File
Upload an image (PNG, JPEG, WebP) or PDF document to embed a tamper-evident authentication signal. You'll receive the signed file and a verification metadata package (sig.json).
- • Supports PNG, JPEG, WebP images and PDF documents
- • Invisible — no visible watermark added
- • Downloads signed file + sig.json metadata
Verify a File
Upload a previously signed file along with its sig.json metadata to check whether the file has been tampered with since signing.
- • Checks whether the signed file still matches its authenticated state
- • Reports similarity score and verdict
- • Multi-page PDF verification supported
- • Requires the original sig.json from signing
How It Works
- 1Upload — Select your image or PDF file and provide a secret key.
- 2Sign — WaveSign embeds an invisible authenticity signal using your key.
- 3Download — Receive the signed file and sig.json verification metadata.
- 4Verify — Later, upload both files to confirm authenticity.